[Freeciv-Dev] Re: different iso drawing algorithms

[Rafa³ Bursig <bursig@xxxxxxxxx>]

Dnia 2002.12.08 17:15 Raimar Falke napisa³(a):
> On Sun, Dec 08, 2002 at 04:29:57PM +0100, Rafa³ Bursig wrote:
> > >> >> If you want have partial acces to pixel ( first metod )you
> must
> > >> >> uncompres sprite and then read those pixels.
> > >> >
> > >> >It wouldn't matter if SDL supports a mask as a clipping
> > >> >object. However it looks like it only support rectangulars.
> > >> >
> > >> Yes but that isn't problem here.
> > >> If you want use that compresion all direct acces to pixels force
> > >> decompess sequence.
> > >> And when you want get only part of pixels ( clipping rect mask )
> > >from
> > >> sprite you must done directly acces.
> > >>
> > >> SDL can support both metod but IMO secound has better performance
> > >> becouse can use RLEACCEL.
> > >
> > >Can you qualify this? How much time do you need for a complete map
> > >canvas redraw if you use RLEACCEL and how without?
> > >
> > I make some test on END_GAME_STATE ( see entire map without
> irrigation
> > , road ,units , cities and FOG !!)
> > I disable dithering becouse for now it work with pixel acces and we
> > want see how fast is RLE
> >
> > I have special function to draw entire screen map ( draw only main
> tile
> > sprites ).
> > Map screen has 640x480 pixels
> >
> > Normal :
> > Redraw time = 87, 90, 88, 93, 97, 91 ms
> > Flush_fullscreen time : 7 ~ 23 ms
> >
> > RLE :
> > Redraw time = 53, 61, 56, 60, 59, 48 ms
> > Flush_fullscreen time : 7 ~ 19 ms
>
> Am I right that you can't use RLE if you draw the irrigation, road,
> units, cities and FOG because these sprites have transparent pixels.
NO... RLE is made for transparent pixels and real those pixel are 
compressed.
If You have more and more transparent pixels the effect will be better 
and better.
I want have entire map that I start new game and disband all unit.

Problem is with FOG becouse SDL havn't mask future ( has simple 
clipping ability )
and when you want create fog of war effect you must use tmp surface 
without RLE compression and that slow down drawing.
Rafal

----------------------------------------------------------------------
Powiedz sobie dobre "Dzien dobry"! >>> http://link.interia.pl/f168b